Prometheus – one could search “autism, dendritic spines” on Google.

I went to PubMed and did that. I see there are a number of animal studies that don’t seem to have any more than a speculative connection to autism. There’s perhaps a connection to Schizophrenia, and maybe a connection to Fragile X.

Is there a study on, you know, human autistics that would tell us this is a common characteristics of autistics?

Even if you find such a difference in autistics, suggesting that it is the difference that explains autism is like saying that hair length is what makes men different to women, frankly. There are many differences and that should be clear by now.

Here is an interesting one regarding knock out mice lacking SHANK1; they show smaller dendritic spines, increased fear response, heightened anxiety, and interestingly enough, improved spatial skills.

http://www.jneurosci.org/cgi/c...../28/7/1697

Neat.

– pD

Why is it not possible that similar structural changes in the neurons with childhood stress/emotional deprivation result in clinical manifestations similar to autism? Certainly in animal studies stress hormones can reduce the numbers and lengths of the dendrites of neurons.

An interesting juxtaposition of unrelated issues. Since we do not know what structural or functional differences are seen in autism, the fact that “stress” can alter neuronal structure is irrelevant.

If that seems counterintuitive, consider this:

If it turns out that autism is the result of a higher than average number of dendrites, the changes seen from stress hormones would be the opposite of what is seen in autism.

Just because something can affect neuronal function or structure does not mean that it can cause a specific neurological disorder or disability. Speculating that this or that might be a cause (or “the cause”) of autism simply because it can affect neurons is nonsensical.

Prometheus

Yet you seem to be trying to … with an obvious bias towards attempting to discount “genetic”. :) Even in your link talking about FAS there is only a small overlap (much more with ADHD). Really you are stumbling on the same problem that autism research has traditionally had, a focus on the more superficial locating of people with symptoms in common (things that have behaviors that “look like”, with an overlap of the symptoms) with the main body of autistic people but with obvious causes that mean these people don’t have much in common with the main autistic body at all. That of course logically includes Fragile-X. Whether or not that serves your agenda. :D

Of course medicine isn’t the only science that has this problem. Astrophysics has “Dark Matter”, it’s own messy placeholder that tends to cause all sorts of problems and misunderstandings as people take it far too literally instead of understanding that it is just a category of matter defined by what are analogous to medical symptoms.

P.S. Fortunately there has been some interesting developments in autism on the hard physiological front as well as interesting work done on understanding thought process and learning in the autistic mind that is also pointing where in the brain to look for physiological differences. Research into use of atypical psychotic drugs to induce “feelings” in autistic patients is an outgrowth of some of this.

No one can define exactly what autism is. Kanner was closest but his defintion was completly removed from all diagnostic criteria in 1994.

Why was Kanner closest? What is the basis for deciding this? Certainly, he was the first to propose the new classification, but it would be difficult to argue that his criteria was better designed and more thought through.

What you want to say is that autism is a cultural construct, which is defined by authority. This is true of a lot of things. Consider, for example, what “dollar” means. It’s a construct, controlled by an authority. Another example: Who defines what “proper English” is and why?

The part that is difficult to get about social constructionism is that social constructs generally have a purpose, and exist in parallel to realities of the physical world. When social constructs are actually useless, they should either be discarded or replaced.